Letters

To support the conclusion of the Intergovernmental Panel on Climate Change (IPCC) that current warming is anthropogenic, William Collins, Robert Colman, James Haywood, Martin R. Manning and Philip Mote assert in “The Physical Science behind Climate Change” that the mismatch between surface and tropospheric warming rates has now been resolved. This claim is not supported by actual observations. According to the April 2006 Climate Change Science Program (CCSP) report, considerable disparity exists between the observed warming-rate patterns and those calculated by greenhouse models. Although the models predict that temperature trends will increase with altitude by 200 to 300 percent, the data from both weather balloons and satellites show the opposite. This result does not deny the existence of a greenhouse effect from the considerable increase in anthropogenic greenhouse gases. But it does suggest that present models greatly overestimate the effect’s magnitude and significance.